In the case of a lithium ion accumulator, the voltage difference between the two cell terminals (poles) of an individual accumulator cell amounts to approximately 3.6 V. In order to obtain the requisite higher voltage level of e.g. approximately 360 V that is needed for many applications such as in the field of automobile propulsion for example, many such accumulator cells (approximately 100 for example) have to be connected electrically in series.
In connection therewith, the accumulator cells or, more generally, the electro-chemical cells can be combined into modules each of which contains a plurality of such electro-chemical cells, wherein the direction in which the mutually neighboring cells are installed alternates so that positive and negative cell terminals are located next to each other in alternating manner. These mutually neighboring cell terminals of opposite polarity are interconnected directly by means of a cell connector for producing the series connection of the cells.
The voltage tapping point incorporating the contact element connected to a base body of the cell connector serves to provide a reliable, operationally secure, low contact resistance connection of the cell connector to a voltage tapping line which itself is connected to an evaluating device of the electro-chemical device.
Differences in electrical potential between the various cell connectors are measured by the evaluating device in order to facilitate monitoring of each individual cell in the electro-chemical device.